I registered just to post here. This has been driving me absolutely nuts. Every time I have a call when in the car and the phone is in my pocket (talking through bluetooth), if my leg so much as twitches I end up muting myself or hanging up. I went from an S3 to the S5. If I get a text while walking and I have music playing or something, any and every button available will be pressed. I have had random gibberish created on my calendar while walking (screen lock hadn't activated yet because I had just put it in my pocket).
ewokuk, any word on what you did? I have played around with as many settings as I can but nothing seems to do the trick. It's a nice phone, but unfortunately this one thing drives me up a wall